The invention relates to a rapeseed (Brassica napus L.) line, plant, progeny and seed of the said line. Specifically, the invention relates to a mutant rapeseed line exhibiting canola type characteristics and adapted to grow in sub-tropical regions, such as India and China. The seeds of the invented line exhibit xe2x80x98Canolaxe2x80x99 type characteristics when grown in the said region.
To increase the consumption of the rapeseed oil and utilization of the meal left after extraction of oil, plant breeders have focussed their efforts in developing varieties of rapeseed having low erucic acid in the oil and reduced glucosinolate content in the meal remaining after oil extraction. (i.e. erucic acid less than 2% by weight in the oil and glucosinolate content of less than 30 micromoles per gram of deffated meal).
Such lines of rapeseed developed commonly in Canada and Europe are termed as xe2x80x9cCanolaxe2x80x9d or xe2x80x9cdouble lowxe2x80x9d lines. Examples of such rapeseed lines can be found in U.S. Pat. No. 5,625,130 and U.S. Pat. No. 5,866,762. The plants provided by these patents have been developed through mutagenesis.
U.S. Pat. No. 5,387,758 issued to Wong et al relates to improved rapeseed plants, seeds, and improved endogenous vegetable oil having unusually low saturated fatty acid content. Further, the plant possesses herbicide tolerance. The total saturated fatty acid content in the oil yielded by the seeds of these plants is in the range of 2-4% by weight and the erucic acid is not more than 2% by weight based on the total fatty acid content. The plants are obtained by mutagenesis.
U.S. Pat. No. 5,767,338 provides Brassica napus plants which produce non-hydrogenated canola oil for food applications. The oil contains 74-80% oleic acid having oxidative stability from 35-40 AOM. This plant again has been grown and tested in various regions in Canada.
U.S. Pat. No. 5,859,350 provides a canola variety producing a seed which yield oil containing less than or equal to 7% linolenic acid and a total glucosinolate content of less than 18 xcexc.mol/g of defatted meal. U.S. Pat. No. 5,866,762 provides Brassica seed having maximum glucosinolate content of 3.4 xcexc.mol/g of seed.
All the patents described above relate to plants, their progenies and seeds which have been improved with respect to their oil quality or provide improved meal. The research or study leading to the development of plants in all the aforegoing patents has been done in Canada or its neighbouring countries. In other words, the plants developed according to the aforegoing patents are capable of being grown in Canada or its neighbouring countries, with a cold or cool climate, but not in countries situated in warmer regions such as India. Attempts to introduce the above or similar exotic canola type plants in India have failed due to substantial differences in the climatic conditions between India and the other canola growing regions.
It is pertinent to note that the climatic conditions in India during winter, when the crop is raised, are completely different as compared to the conditions prevailing in Canada in summer, when main crop of canola is grown as shown in Table 1 (a andb) and Table 2 (a andb) below.
The rapeseed crop in India is sown in the month of October when the temperature is suitable for germination and the crop is harvested at the end of winter, i.e. in March-April.
When Canadian Canola type varieties cultivated in India under the above conditions, it is observed that the plant continues to flower till late in the season. In February, the temperature starts rising and reaches around 40xc2x0 C. by end of March. This forces the crop to attain maturity. It is contemplated that rise in temperature, after flowering could be responsible for poor seed setting. Consequently, increased incidence of flower abortions, poor seed setting, seed size and seed yield etc. are observed in these varieties. Relationship between the curtailed pod length growth at high temperature and also abortion has been explained by Pechan P. A. and Morgan D. G. [J. of Experimental Botany 36:458-468, 1985].
It has emerged that the acclimatization of exotic B.napus L. lines like canola to traditional mustard growing areas in India has almost no scope for commercial exploitation. Agarwal, P. K. [Indian J. Experimental Biology, 9: 252-254, 1971].
Breeding Challenges
Developing widely adaptable canola quality rapeseed for commercial cultivation in the Indian sub-continent is a challenging task.
The rapeseed varieties released in India grow only northern/north-western regions of the country where cool climate is available for production of commercially acceptable seed yield. These lines, however, do not possess the Canola quality characteristics which are desirable from quality point of view.
Thus, there is a need to develop canola-type rapeseed lines that are suitable for commercial cultivation in sub-tropical regions like India with seed yield comparable to that of native Indian rapeseed-mustard varieties and also reatin their canola type characteristics.
Objects
The main object of the invention is to provide mutant seeds of Brassica napus that exhibit canola type characteristics and are suitable for commercial cultivation in sub-tropical regions.
Another object is to provide mutant seeds of Brassica napus that exhibit canola characteristics and mature within 150 days after sowing (DAS) under sub-tropical conditions.
Yet another object is to provide mutant seeds of Brassica napus seed that yield oil whose erucic acid content when grown in sub-tropical regions does not exceed 2%.
Still another object is to provide mutant seeds of Brassica napus wherein seed contains 9.4 micromoles of glucosinolate per gram of seed which is almost equivalent to 17 micromoles of glucosinolate per gram of defatted meal.
Further object is to provide mutant lines of Brassica napus having stable morphological and agronomic characteristics.
Yet another object is to provide mutant lines of Brassica napus seed yielding vegetable oil having improved distribution of fatty acids.
Another object is to provide mutant lines of Brassica napus and producing seed that contains low levels of erucic acid.
These and other objects of the invention will be apparent to those skilled in the art from a reading of the following description and the appended claims.
The invention relates to mutant seeds of (Brassica napus L.) plants and progenies, which have been adapted to grow in sub-tropical regions. The mutant seeds of the invention have been designated as NUDB-38. The mutant seeds of the invention yield rapeseed oil containing low level of erucic acid. The defatted meal also contains low levels of glucosinolates, when grown in sub-tropical regions. Further, the plants of the invented lines mature within 150 days after sowing. The seed yield of the plants of the invention is better than the native Indian rapeseed Brassica napus L.
The present invention relates to mutant seeds of Brassica napus designated as NUDB-38, these seeds produce plants that have been acclimatized to growing in sub-tropical regions where rapeseed and the Indian mustard is commonly grown. The oil from these mutant seeds of NUDB-38 contain less than 2% erucic acid. The defatted meal of the seeds contains less than 17 micromoles of glucosinolates per gram of defatted meal. The plants of the invented line complete 50 percent flowering between 48-60 days after sowing and seed matures within about 114-141 days (Table 3). The seed yield of the mutant plant is also comparable to that of native mustard which is grown extensively in the region.
As used herein, the term xe2x80x9cacclimatizedxe2x80x9d would mean adapted to growing in Indian environment, especially in the regions where rapeseed is grown in India.
xe2x80x9cCanola characteristicsxe2x80x9d refers to the rapeseed plants of Brassica genus which produce seed that contains less than 2 percent erucic acid by weight in its oil and contains less than 30 micromoles of total glucosinolate in its defatted meal.
Mustard refers to the plants of the cultivated Indian mustard (Brassica juncea L.) varieties.
xe2x80x9cDay lengthxe2x80x9d refers to availability of sunshine per day in hours.
xe2x80x9cEarly floweringxe2x80x9d means the commencement of flowering in the invented line earlier than the check and is referred in number of days.
xe2x80x9850% Floweringxe2x80x99 refers to the initiation of flowering in 50 percent of the plant population.
xe2x80x9cLong-day plantxe2x80x9d refers to plants that requires more number of sunshine hours per day to flower.
A xe2x80x9clinexe2x80x9d in the present invention relates to a group of plants that display little or no genetic variations between the individuals. Such lines have been created in the present invention by several generations of self-pollination and selection from a single plant derived from a mutagenized seed.
xe2x80x9cMaturityxe2x80x9d refers to stage of a plant when it has produced seed which are fully developed and the plants are ready for harvest.
The terms xe2x80x9ccultivarxe2x80x9d and xe2x80x9cvarietyxe2x80x9d refer to a line used for commercial cultivation.
xe2x80x9cProgenyxe2x80x9d refers to the plants and seeds of all subsequent generations resulting from a single plant.
xe2x80x9cMustard growing regionxe2x80x9d refers to the regions in India which cover 90 percent acreage of total rapeseed-mustard area.
xe2x80x9cSelfedxe2x80x9d refers to self-pollination.
xe2x80x9cSunshine hoursxe2x80x9d means the time between the sunrise and sunset.
xe2x80x9cShort day conditionsxe2x80x9d refers to climatic conditions with less number of sunshine hours per day.
xe2x80x9cSub-tropicalxe2x80x9d means a region preferably grown between 21xc2x0 N. and 30xc2x0 N. latitude and between 72xc2x0 E. to 81xc2x0 E. longitude.
The novelty of the invention resides in developing an unique line of Brassica napus plants having the following distinguishing characteristics:
(i) the plants of the invention unlike their counterparts in Canada or Europe have been adapted to grow in completely different agro-climatic conditions, i.e. the sub-tropical regions.
(ii) the plants grow well and flower with 5-10 hours of day length as opposed to the parent canola line which requires 15 to 17 hrs of day length for its growth and flowering.
(iii) the plants mature within 114-141 days after sowing under sub-tropical conditions as against about 85-104 days taken by the canola varieties in Canada.
(iv) the seed produced from the invented line retains the canola character, yield oil containing less than 2% erucic acid and the meal left after extraction of oil contains less than 30 micromoles of glucosinolates per gram.
The plants of the invention have been developed through chemical mutagenesis. Out of the mutagenised population, one distinct mutant plant was isolated, stabilized and tested in various climatic conditions to ascertain its adaptability. The seeds of the invention designated as NUDB-38 has been identified.
Accordingly, the invention provides mutant Brassica napus line exhibiting the following characteristics:
a) capable of being grown in sub-tropical regions,
b) having average seed yield of about 1815 kg/ha (936 to 2863 kg/ha).
c) seed maturing between 114 to 141 days after sowing (DAS), and
d) producing seeds having not more than 0.1% erucic acid in oil and average of about 17 micro moles glucosinolates per gram of defatted meal.
e) producing seeds having primary and secondary, reticulation on its surface with shallow and circular pits.
In an embodiment, the plants of Brassica napus line are capable of growing in sub-tropical regions selected from Australia, China, India and USA.
In another embodiment, the seed of the plant as described herein above has been deposited at National Bureau of Plant Genetic Resources (NBPGR), New Delhi and allotted a registration no. INGR 01048. The seeds are also deposited under the Budapest Treaty at International Depository (American Type Culture Collection, USA) and have been allotted Patent Deposit Designation: PTA-4645. The deposited seeds will remain readily available to the public for a term of 30 years and for at least 5 years after the last request. Applicants also warrant the permanence of the deposit viability and ready accessibility thereto by the public if a patent is granted, under conditions which assure (a) that access to the culture will be available during pendency of said patent application to one determined by the Commissioner to be entitled thereto under 37 C.F.R. 1.14 and 35 U.S.C. 122, and (b) that all restrictions on the availability to the public of the above-mentioned culture will be irrevocably removed upon the granting of a patent.
The seed deposit was made under the Budapest Treaty. The sample deposit is viable and will be maintained for a period of at least 30 years from the date of the deposit, or five years after the most recent request for a sample, whichever is longer. If the culture should die or become destroyed during the effective term, it will be replaced. The strain will be made available if a U.S. Patent is issued citing the strain or if the U.S. Patent and Trademark Office so instructs the release of the strain.
The invention makes possible the commercial production of canola quality, high yielding rapeseed (Brassica napus L.) in the traditional mustard growing areas in India or in other similar agro-climatic conditions elsewhere.
The invention is further illustrated with reference to the accompanying drawings, examples and description. These illustrations can be practically used, by a person trained in plant breeding art, in developing novel rapeseed line.